Hard disk drives are used in many electronic devices such as desktop computers, laptop computers, MP3 players, Global Positioning Systems, Personal Digital Assistant devices and other devices for data storage. As a key component of hard disk drive, a magnetic head reads and writes the data from and onto a magnetic disk while the magnetic head flies above the disk at a well defined distance. This distance is also called the fly height in the data storage industry. The fly height is a function many factors, including the patterned shape of the air bearing surface, various levels of cavities on the air bearing surface, the depth of the cavities, and the rail width. The ion milling process is one of the processes in conjunction with the photo lithography process used to create a cavity with a designed depth and shape on an air bearing surface.
Ion milling is a process applied to an object under vacuum whereby a selected area of the object's surface can be bombarded by an energetic beam of ions. This bombardment removes material from the object's surface. Through the process of ion milling, a slider's air bearing surface will be etched into a pre-determined contoured shape.
However, there exist many limitations to the current state of technology with respect to ion milling. For example, these different processing steps of different design considerations create functionality complications in regards to the hard disk drive.